WASHINGTON, DC (NEXSTAR) — Health officials say contact tracing is key to preventing large outbreaks of the coronavirus as Americans venture out of their homes and back into the workplace.

One of the most reliable tools for figuring out where people have been and who they have come in contact with is their cell phone, which tracks their every move.

However, a group of top Senate Republicans fear tracing could easily become a violation of consumers’ privacy.

“If someone is being asked to sacrifice his or her privacy, they need to know about it,” said Sen. Roger Wicker, R-MS. “We need to make sure that our privacy is protected, and we’re not signing something away unknowingly.”

Wicker is among the senators who introduced legislation that would require consumers to agree to mobile phone-based contact tracing before companies can share the data with government. They could also opt out at any time.

The bill also directs companies to tell their customers how they plan to use the information and who will have access to it. It would require companies to delete the data they have collected once it is no longer needed for the public health emergency.

“Right now, these ideas are in their infancy, and we’re ready to hear all sides,” Wicker said.

While Congress continues to debate data privacy protection, apps designed to track coronavirus are popping up across the country.

“If you’re going to use an app that traces everywhere that you’ve been and everyone you’ve been content with, that raises privacy concerns,” said James Grimmelmann, an internet law professor at Cornell University.

Grimmelmann said the apps notify users of their possible exposure and urge them to get tested, but he warns there are limits to its effectiveness.

“It can’t substitute for the legwork of actually finding out everywhere somebody has been,” Grimmelmann said.

That’s why many in Congress are also pushing for more widespread testing.